Trying to get to the bottom of life, NASA scientists have reproduced cytosine, thymine, and uracil - three key components of life found in both DNA and RNA in a laboratory in Moffett Field, California.

“We have demonstrated for the first time that we can make
uracil, cytosine, and thymine, all three components of RNA and
DNA, non-biologically in a laboratory under conditions found in
space,” said Michel Nuevo, research scientist at NASA’s Ames
Research Center.

Scientists in space-like conditions lab deposited an ice sample
containing pyrimidine on a cold substrate to discover that such
approach produces these essential ingredients of life. The
molecule pyrimidine is found in meteorites, although scientists
still do not know its origin.

By exposing, pyrimidine, a ring-shaped molecule made up of carbon
and nitrogen to high-energy ultraviolet (UV) photons from a
hydrogen lamp, scientists were able to break chemical bonds in
the ice's molecules into fragments. The broken fragments then
reassembled themselves in such a way as to form new compounds,
such as uracil, cytosine and thymine.

NASA also discovered that pyrimidine is much less vulnerable to
destruction by radiation if it’s frozen in ice mostly consisting
of water, but containing ammonia, methanol or methane.

“The chemistry of ice exposed to ultraviolet radiation may be
an important linking step between what goes on in space and what
fell to Earth early in its development,” said Christopher
Materese, researcher at NASA involved in the experiments, adding
that the question of life on Earth is still unanswered.

“Nobody really understands how life got started on Earth. Our
experiments suggest that once the Earth formed, many of the
building blocks of life were likely present from the beginning.
Since we are simulating universal astrophysical conditions, the
same is likely wherever planets are formed,” said NASA
researcher Scott Sandford.